Mixing of Fluorescent Dye in Stirred Tank Reactor

Mixing of Fluorescent Dye in Stirred Tank Reactor A fluorescent dye injected into a tank of stirred liquid creates a pattern that resembles a green apple. The demonstration, conducted by Rutgers researchers from the NSF Engineering Research Center on Structured Organic Composites (C-SOC), shows how liquids mix in a typical pharmaceutical manufacturing operation. Engineers will use such studies to help drug makers improve product uniformity. In this view, a 4-blade impeller attached at the bottom of the vertical shaft, visible at the center of the image, draws fluid from above and creates outgoing ripples in the flow. Dye injected from above is rapidly advected around a toroidal shell, but penetrates slowly into the interior: this separation between the outside and the inside of mixing regions represents a bottleneck to processing and a challenge to the generation of reproducible product uniformity. The NSF Engineering Research Centers (ERC) program established C-SOC to study the nature of finely ground granular materials and other substances that form the core of drug tablets, processed foods, agricultural chemicals and other "composite organic" products. In addition to improving the quality and consistency of such materials, the center will develop more consistent and cost-effective manufacturing techniques than methods based largely on trial and error. To learn more about work at this center, visit the C-SOC Web site. Further information about the NSF Engineering Research Centers program, including a list of the centers currently funded and links to their Web sites, is available at http://www.nsf.gov/funding/pgm_summ.jsp?pims_id=5502. (Date of Image: unknown) [One of several related images. See Next Image.]